The Lake County Coroner's Office has identified the steelworker who died at ArcelorMittal Indiana Harbor in East Chicago early Monday morning as Alfred Cadena, a 61-year-old East Chicago resident.

The cause and manner of death were not immediately available. Chief Deputy Coroner Scott Sefton said the results were pending a standard toxicology test, and would not be available for 30 to 45 days.

At 1:28 a.m. Monday, Cadena, a line operator, was driving a Taylor Dunn buggy at the steel mill and drove under a stationary scrap trailer for unknown reasons, United Steelworkers Union Local 1010 President Tom Hargove said.

He and his coworkers attached a scrap piece of steel that was broken off from a weld to the buggy to pull it to the trailer, Hargrove said. After a worker disconnected the strip while Cadena was trying to position the buggy to move out of the area, the buggy suddenly went forward under the trailer.

"After initial response by coworkers, he was transported by plant ambulance and plant medical responders to a local hospital," Hargrove said. "An official cause of death has not been determined at this point in time."

The last United Steelworker Local 1010 union member to die at ArcelorMittal Indiana Harbor was 33-year-old cold strip mill employee Jason Ham, who died in an accident seven years ago in October. In 2014, technician Robert "Lane" Watts died as a result of thermal injuries he suffered after falling into a sinkhole and 39-year-old ironworker Michael Samuelson was crushed under a falling 3.65-ton metal panel at the sprawling steel mill in East Chicago's Indiana Harbor neighborhood.

"Anytime you have a fatality, your safety system has failed," Hargrove said. "Our hearts go out to the family. We work very hard everyday, company and union, on safety and sometimes it's just not enough. Bad things happen very fast, but we will not give up. The consequences are too great. We must work together even harder, company and union, to prevent this from happening again."

The Indiana Occupational Safety and Health Administration is investigating the fatal accident, spokeswoman Molly Deuberry said.